CHAPTER XXXVI. 533 



the upgraded alcohols to paraffin. Sections are stained for one hour in 

 saturated magenta, and are placed for five to ten minutes in a saturated 

 solution of picric acid in water, 1 part, and saturated aqueous indigo 

 carmine, 2 parts. They are washed in water and are decolourised in 

 absolute alcohol and then in clove oil, and are mounted in balsam. 



1002. Ciliates. Osmic acid fixation is amongst those best suited 

 for the ciliates, generally being employed either as vapour or wet 

 on the slide. Many forms may be mixed with serum water (serum 

 1 part, water, 20 parts), and then spread on slides and fixed either 

 in the osmic vapour or by means of Schaudinn's solution. Bouin's 

 fluid is also very suitable for fixation of many forms such as Opalina 

 and Lophomonas. Tissues are best fixed in either 10 per cent, 

 formol saline or Flemming's solution. 



Staining may be by means of methyl green or any of the stains 

 used for amoebae. In many cases Hollande's chloro-carmine gives 

 very satisfactory results. 



1003. Flagellata. For the majority of these forms the technique 

 employed for the study of the trypanosomes may be used. Slides 

 may be coated with either serum water or a very thin layer of 

 glycerin albumen. A drop of the fluid containing the flagellates 

 such as blood may be spread quickly over it before drying occurs, 

 and the slide at once placed in Schaudinn's sublimate or Flemming's 

 solution for varying periods. Slides are then treated with upgraded 

 alcohols, the weaker ones containing a little iodine. They are then 

 brought down to water and stained with Heidenhain's iron hsema- 

 toxylin. Dried blood films prepared in the usual manner may be 



fixed in alcohol-ether or absolute methvl alcohol and stained with 



/ 



Giemsa's method. 



1004. Hsemamcebse.- -These forms, the principal of which are the 

 well-known malarial parasites, will be found in the blood, and 

 heematological methods must be used. 



Blood is spread in thin layers on slides by placing a drop at one end 

 of the slide and touching it with the end of another. The blood will 

 spread out in a thin layer and may then be drawn across the slide when 

 a thin, usually one-cell, layer is obtained. Films made by streaking a 

 drop of the blood over a slide by means of cigarette paper are also 

 good. 



Such films are best fixed either in alcohol-ether (equal parts of each) 

 for half an hour to one hour, or pure methyl alcohol free from acetone 

 one hour. For a single method of staining such films, probably Eees' 

 thionin is the best. It is prepared as follows. Thionin 1-5 grms., 

 absolute alcohol 10 c.c., 5 per cent, carbolic acid solution. 100 c.c. 

 Dissolve the thionin in the alcohol and add the carbolic solution. It is 



